Process for making piston-rings.



J. FLAMIVIANG.

PROCESS FOR MAKING PISTON RINGS.

APPLICATlON FILED JUNEG. 1917.

1,295,1{k7 Patented Feb. 25, 1919.

UNITED STATES PATENT OFFICE.

JOHN FLAMMANG, OF ST. LOUIS, MISSOURI, ASSIGNOR T0 INLAND MACHINE WORKS,OF ST. LOUIS, MISSOURI, A CORPORATION OF MISSOURI.

PROCESS FOR MAKING PISTON-RINGS.

Specification 01 Letters Patent.

Patented Feb. 25, 1919.

To all whom it may concern:

Be it known that I, JOHN FLAMMANG, a citizen of the United States,residing at the city of St. Louis and State of'Missouri, have invented anew and useful Process for Making Piston-Rings, of which thefollowing-is a specification.

This invention relates to the art of manufacturing piston rings, and itconsists in the novel method of procedure in manufacturing piston ringsin order to characterize them so that when applied to use within acylinder the overlapping portions of the rings will form a perfect seal,and the pressure of the rings against the cylinder will be properlydistributed and apportione throughout their circumference.

An object of the invention is to provide a novel process for use in theart of manufacturing piston rings, whereby rings are produced bysubjecting split rings having overlapping end portions to torsionalaction whereby they will be pressed together by the initial resiliencyof the metal, and finishing the ring after inversion of the overlappingends thereof.

Another object of the invention is to provide aprocess for use in theart of manufacturing pistonrings consisting in subjecting split ringshaving overlapping end portions to torsional action whereby they arepressed together by the initial resiliency of the metal, and thenchanging the shape of the ring to give the greater portion thereofaconcentric shape and leaving portions of the overlapping ends thereon ofsmaller radii of curvature than the remaining portions of the ring, sothat ,when the ring is compressed within a cylinder ofthe size for whichit is intended it will impart, against the cylinder wall a uniformpressure all around without' variation in the pressure, as in the caseof rings ofusual construction.

Other objects will appear from the follow-' ing description, withoutspecific mention thereof.

In the accompanying drawings, illustrat ing a ring in the differentstages of its manufacture,

Figure l is an elevation looking toward the periphery of an annularcasting from which the ring is manufactured.

Fig. 2 is an elevation looking toward the I periphery of the castingafter it has been out or split for a considerable portion of itscircumference to provide overlapping end portions.

Fig. 3 is an elevation looking toward'the periphery of the ring beforebeing expanded,-

showing the overlappingend portions of F1g. 2 inverted on opposite sidesof each other from their original positions.

Fig. 4 is an elevation looking toward the periphery of an annularcasting split or cut to provide "overlapping end portions. of uniformwidth throughout their length, thus differing from the constructionshown in Fig. 2 in which the overlapping end portions are tapered. I

Fig. 5 is a side elevation of the ring before being expanded and havingthe end portions thereof set upon shorter radii of curvature'than theremaining portions of the expanded ring. I

Fin. 6 is a view illustrating the ring upon an expanding arbor by whichthe shape of the ring is changed so that the end portions thereof are onshorter radii of curvature than the remaining portions of the ring.

Fig. 7 is a view of the ring detached from ing the shape of the finishedring.

Fig. 8 is'a view illustrating the ring compressed 'within a cylinderofthe size for which it is intended.

In Fig. 1 there is'illustrated an annular casting consisting of twointegrally united ofl'set portions. At the point of union there isformed'at one side a beveled shoulder 1 and on the opposite edge abeveled shoulder 2 which, in the finished form of the ring at least andpreferably in its initial stage, matches the shoulder 1 so that when thering blank is split and the overlapping ends thereof are inverted theshoulder 1 willextend within or under the shoulder 2 and thus limitoutward expansion of the end portion containing the shoulder 1.

.The ring blank also includes at another portion of its circumference abeveled shoulder 3 and On the opposite edge a beveled shoulder 4 which,in the finished form of the ring at least and preferably in its initialstage, matches the shoulder 3.

clearly illustrated in Fig. 2, in which the slot 5 extends spirally fromthe shoulder 1 to the shoulder 4:, thus forming two overlapping taperedend portions separatedby the width of the slot 5. However, it is notessential that the overlapping end portions be tapered and they may bemade of uniform width throughout their length if desired. In Fig. 41have illustrated a ring blank precisely similar to the ring blank shownin Fig. 2, with the exception that the overlapping end portions thereofare of unlform thickness throughout their length. Since this is the onlyparticular in which the ring blank illustrated in Fig. 4 differs fromthe one illustrated in Fig. 2, the same reference characters are appliedto both views of the 1 drawing. i

'. The next step in the manufacture of the ring consistsin twisting orinverting the ring blank to place the overlapping ends thereof onopposite sides from their initial positions so that they will be pressedtogethe'r by the resiliency of the metal. The ring blank thus twisted orinverted is illus trated in Fig. 3', which also illustrates the 'ringblank after it has been dressed or faced .ofi' preparatory to beingexpanded for the purpose of giving it the shape of the finished ring.Fig, 5 illustrates the ring blank of Fig. 3. in side elevation, showingthe shoulders I and 4 extending under or within the shoulders 2 and 3.

The ring blank is then placed upon an expanding arbor, as illustrated inFig. 6, by which uniform radial pressures are applied 'to portions ofthe ring, but which leaves the extremities of the overlapping portionsof .the ring curving on shorter radii of curvature than the remainingportions of the ring. While the extremities of the overlapping portionsof the ring are somewhat modified they remain nevertheless uponapproximately the same radii'of curvature as they were originally, whichis approximately the proper radii of curvature for a'piston and cyllnderof the size for which the ring is constructed. While upon the expandingarbor, the ring is subjected to heat orother- .wise treated to set themetal in its changed shape so that when the ring is removed from thearbor it will retain the shape given it thereby, in which theextremities of the overlappm portions of the ring are upon shorter r aii of curvature than the remaining portions of the ring, the saidshorter ;radii of curvature being approximately the --radii of curvatureof the cylinder for which the rln .claims.

and 3, or of uniform width throughout their length as illustrated inFig. 4. The ring illustrated in Fig. 7 is the finished ring and is readyto be applied to a piston and placed within the cylinder. When the ringis placed within the cylinder it is compressed to approximately thedimensions illustrated in Fig, 5, as will be clearly understood byreference to Fig. 8, in which the finished ring is illustrated upon thepiston and within the cylinder.

From the foregoingit will be understood that I have p-rovlded a simpleand inexpensive procedure for constructing a ring, so that theoverlapping portions thereof will be pressed together by the inherentresiliency of y the metal without changing the molecular construction byheat or other treatment. The variation in .the radii of curvature of theoverlapping portions of the ring may be effected otherwise than by thespecific treatmentdescribed, as, for instance,

by peening, or by hammering, though I have found in practice that themode described is highly satisfactory.

It is apparent that the order of the different operations may be" variedand that the ring may be set in its expanded shape to vary the radiiofcurvature before the ring blank has been twisted or faced off to theform illustrated in' Fig. Obviously, the

twisting or inversion of the ring to place the overlapping ends thereofon opposite sides from their initial positions, so that Y they will bepressed together by the inherent resiliency of the metal, may beeffected after removal from the expanding arbor instead of before beingplaced upon the, arbor.

There are other variations which will be readily apparent to thoseskilled'in the art to which this invention relates, and which do notrequire specific mentionbut which I are clearly within'the scope of mypresent Therefore, I do not. confine myself to any s ecific order inwhich the operations are per ormed,-but what I claim and desire tosecure by Letters Patent is 1. The process of forming a piston ring withoverlapping end portions pressed together by the initial resiliency ofthe metal, which comprises splitting a ring on a cute):-

tending circumferentially to provide the.

overlapping end portions, inverting the overlapping end portions toplace them on opposite sides of each otherf'rom their originalpositions, and finishing the ring While;

the overlapping end portions are on opposite sides of each other fromtheir original positions and are pressed together by the initialresiliency ofthe metal.

2. The process of forming a piston ring having overlapping end portions,which comprises splitting 'a solid ring in a cut extendingcircumferentially to provide overlapping end portions, inverting thesplit ring thereby formed to place the overlapping end portions onopposite sides of each other from their original positions, and facingoff the ring while the overlapping ends thereof are inverted and arepressed together by the initial resiliency of the metal to form parallelside walls on the ring.

3. The process of forming a piston ring having overlapping end portions,which comprises splitting a solid ring in a long out extendingcircumferentially, inverting the split ring to place the overlapping endportions thereof on opposite sides of each other from their originalpositions, facing off the ring in its inverted position to form parallelside walls, and expanding the ring to a size in excess of the cylinderfor which it is intended.

4. The process of forming a piston ring expanded to a size inexcess ofthe cylinder for which it is intended and having overlapping endportions, Which comprises invertlng the overlapping end portions toplace them on opposite sides of each other from their originalpositions, whereby they will be pressed together throughout their lengthby the initial resiliency of the metal, and facing oil the side edges ofthe ring while the overlapping ends thereof are inverted from theiroriginal positions and pressed together by the initial resiliency of themetal to form parallel side Walls of the ring.

5. The process of forming a piston ring having overlapping end ortions,which comprises splitting a solid rlng in a long cut extendincircumferentially, invertin the overlapping end portions formed there yto place them upon opposite sides of each other from their originalpositions, and forming for the ring in its inverted form. a

6. The process of forming a piston rin having overlapping end portions,Whic comprises splitting a solid ring in along .cut extendingcircumferentially to form the verlapping end portions, inverting theoverlapping end portions to place themon opposite sides of each otherfrom their original positions, expanding the rin by the application' ofradial pressure ereto, and thereafter-treating the ring to set thematerial thereof to cause'it to retain said expanded form. v H

7. The process of forming a piston ring, which consists in splitting asolid ring circumferentially to form overlapping" and portions, twistingthe ring to place the overlapping end portions on opposite'sides of eachother from their original positions, 7

parallel side walls for the ring, while t e overlapping ends thereof areinformin lapping end Verted as aforesaid, expanding the ring to a sizein excess of the cylinder for which it is intended, while leaving theextremities of the overlapping portions on shorter radii of curvaturethan the remaining portions of the ring, and treating the ring to setthematerial thereof in its expanded form.

8. The process of forming a piston ring, which consists in splitting aring circumferentially for a portion of its circumference to provideoverlapping end portions, inverting the overlapping end portions toplace them on opposite sldes of each other from their originalpositions, expanding the ring by the application of uniform. radialpres; sures thereto, leaving the end portions of the ring upon shorterradii of curvature than the remaining portions of the expanded ring, andexposing the ring to the action of heat to set the material thereof inthe overlapping end portions, inverting the overportions to place themon opposite sides of each other from their original positions, formingparallel side walls upon the ring while the overlapping ends thereof areinverted as aforesaid, expanding the greaterportion of the ringto a sizein excess of the cylinder for which it is intended while the extremitiesof the overlap ping portions remainupon shorter radii of curvature thanthe remaining portions of the ring, and treatin the ring to set themetal thereofin the s ape aforesaid.

10. The process of forming a piston ring having overlapping endportions, which comprises splitting a solid ring in a cut extendingcircumferentially to provide the ,overlapping end-portions, invertingthe split rin thereby formed to place the overlapping en portions onopposite sides of each other from their original positions, expandingthe ring by the application of radial pressure thereto untilthe greaterportion of the ring is upon radii of curvature in excess of the radii ofcurvature of the cylinder for which the ring is intended leaving the endportions of the ring upon' shorter radii of curvature 1 than theremaining portions, treating the --ring to set thematerial thereof inthe form aforesaid, and facing off the side edges of the. rin' while theend portions'thereof are invert from their original positions to formparallel side walls.

In witness whereof, I have signed this specification. 1

p FLAMMANG.

